Early childhood caries (also referred to herein as “ECC”), which involves tooth decay of primary teeth in young children, is a major public health problem. See Centers for Disease Control and Prevention: Conference, Atlanta (September, 1994); Tinanoff et al., “Early Childhood Caries: Overview and Recent Findings,” Pediatric Dentistry 19:12-16 (1997); Tinanoff, “Introduction to the Early Childhood Caries Conference: Initial Description and Current Understanding,” Commun Dent Oral Epidemiol 23(Suppl. 1):5-7 (1998). A reliable test for caries activity before appearance of lesions does not exist.
Glucosyltransferases (“Gtfs”) play an essential role in the etiology and pathogenesis of dental caries by promoting the sucrose dependent adherence of cariogenic streptococci on smooth surfaces and the subsequent development of dental plaque (Smith et al., “Effects of Local Immunization with Glucosyltransferase on Colonization of Hamsters by Streptococcus mutans,” Infect Immun 37:656-661 (1982); Hamada et al., “Virulence Factors of Streptococcus mutans and Dental Caries Prevention,” J Dent Res 63:407-411 (1984); Tanzer et al., “Virulence of Mutants Defective in Glucosyltransferase, Dextran-Meditated Aggregation, or Dextranase Activity, in Molecular Basis of Oral Microbial Adhesion, Mergenhagen et al., eds., Washington, D.C.: American Society for Microbiology, pp. 204-211 (1985); Tsumori et al., “The Role of the Streptococcus mutans Glucosyltransferases in the Sucrose-Dependent Attachment to Smooth Surfaces: Essential Role of the Gtf-C Enzyme,” Oral Microbiol Immunol 12:274-280 (1997)).
The colonization of smooth surfaces by mutans streptococci has been correlated with high caries activities in young children and the synthesis of insoluble glucan has been shown to contribute to caries development in infant and toddlers by increasing the adherence of mutans streptococci and their accumulation in dental plaque (Alaluusua et al., “Streptococcus mutans Establishment and Dental Caries in Children from 2 to 4 Years Old,” Scan J Dent Res 91:453-457 (1983); Köhler et al., “The Earlier the Colonization by Mutans Streptococci, the Higher the Caries Prevalence at 4 Years of Age,” Oral Micrbiol Immunol 3:14-17 (1988); Mattos-Graner et al., “Water-Insoluble Glucan Synthesis by Mutans Streptococcal Strains Correlates with Caries Incidence in 12- to 30-Month-Old Children,” J Dent Res 79:1371-1377 (2000)).
Gtf B, C, and D are produced by cariogenic streptococci such as Streptococcus mutans and S. sobrinus (Hamada et al., “Biology, Immunology, and Cariogenicity of Streptococcus mutans,” Microbiol Rev 44:331-384 (1980); Loesche, “Role of Streptococcus mutans in Human Dental Decay,” Microbiol Rev 50:353-380 (1986)). The mutans streptococci synthesize at least three gtfgene products (Loesche, “Role of Streptococcus mutans in Human Dental Decay,” Microbiol Rev 50:353-380 (1986); Hanada et al., “Isolation and Characterization of the gtfC Gene, Coding for Synthesis of Both Soluble and Insoluble Glucans,” Infect Immun 56:1999-2005 (1988)). GtfB polymerizes an insoluble glucan composed predominantly of α1,3 linked glucose moieties. GtfD produces a soluble glucan, which has predominantly α1,6 linked glucosyl units, and GtfC synthesizes a polymer with a mixture of α1,3 linked glucose moieties and α1,6 linked glucose (Loesche, “Role of Streptococcus mutans in Human Dental Decay,” Microbiol Rev 50:353-380 (1986); Hanada, et al., “Isolation and Characterization of the Streptococcus mutans gtfD Gene, Coding for Synthesis of Primer Dependent Soluble Glucan Synthesis,” Infect Immun 57:2079-2085 (1989)). Although Gtf enzymes are found in whole saliva and in salivary pellicle formed in vivo and in vitro, the source and type are undetermined. There could be numerous sources of Gtf in saliva, and salivary Gtf could be derived from S. mutans, S. sobrinus, and S. sanguinus (Hamada, et al., “Biology, Immunology, and Cariogenicity of Streptococcus mutans,” Microbiol Rev 44:331-384 (1980); Loesche, “Role of Streptococcus mutans in Human Dental Decay,” Microbiol Rev 50:353-380 (1986); Vacca Smith et al., “In situ Studies of Pellicle Formation on Hydroxyapatite Discs,” Archs Oral Biol 45:277-291 (2000)). Evidence shows that the Gtf activity found in salivary pellicle has many properties similar to those of GtfC (Vacca Smith et al., “Characterization of Glucosyltransferase of Human Saliva Adsorbed onto Hydroxyapatite Surfaces,” Caries Res 30:354-360 (1996)).
In a recent study, the concentration of mutans streptococci in the saliva of caries-free and caries-active toddlers was quantified, and the bacteria were isolated and analyzed for their ability to produce glucan and adhere to glass surfaces (Mattos-Graner et al., “Water-Insoluble Glucan Synthesis by Mutans Streptococcal Strains Correlates with Caries Incidence in 12- to 30-Month-Old Children,” J Dent Res 79:1371-1377 (2000)). These investigators found positive correlations between mutans streptococci levels in saliva and caries incidence, between Gtf activities of the mutans streptococci and caries incidence, and between Gtf activities of the bacteria and the abilities of the bacteria to adhere to glass surfaces (Mattos-Graner et al., “Water-Insoluble Glucan Synthesis by Mutans Streptococcal Strains Correlates with Caries Incidence in 12- to 30-Month-Old Children,” J Dent Res 79:1371-1377 (2000)).
Gtf B, C and D are essential for the expression of virulence of mutans streptococci (DeStoppelaar et al., “Decrease in Cariogenicity of a Mutant of Streptococcus mutans,” Archs Oral Biol 16:971-975 (1971); Hamada et al., “Virulence Factors of Streptococcus mutans and Dental Caries Prevention,” J Dent Res 63:407-411 (1984); Tanzer et al., “Virulence of Mutants Defective in Glucosyltransferase, Dextran-Meditated Aggregation, or Dextranase Activity, in Molecular Basis of Oral Microbial Adhesion, Mergenhagen et al., eds., Washington, D.C.: American Society for Microbiology, pp. 204-211 (1985); Yamashita et al., “Role of the Streptococcus mutans gtf Genes in Caries Induction on the Specific-Pathogen-Free Rat Model,” Infect Immun 61:3811-3817 (1993)).
The best predictor of future caries experience thus far involves assessing the presence of carious lesions already present on tooth surfaces (Grainger et al., “Determination of Relative Caries Experience,” J Can Dent Ass 26: 531 (1960); Stamm et al., “The University of North Carolina Caries Risk Assessment Study: Final Results and Some Alternative Modeling Approaches,” in Cariology for the Nineties,” Bowen et al., eds., Rochester, N.Y.: University of Rochester Press, pp. 209-234 (1993); Hausen, “Caries Prediction-State of the Art,” Community Dent Oral Epidemiol 25:87-96 (1997); Powell, L. V., “Caries Prediction: A Review of the Literature,” Community Dent Oral Epidemiol 26:361-371 (1998); Messer, L. B., “Assessing Caries Risk in Children,” Aust Dent J 45:6-10 (2000)). That is, current diagnostic procedures are limited to confirming the existence of active dental caries after damage has already occurred.
Despite the knowledge of causative factors for caries development, there exists a significant need for a quick and convenient test that can accurately assess caries activity chairside in affected individuals and be used reliably to predict the chance of developing carious lesions prior to onset.
The present invention is directed to overcoming these and other deficiencies in the art.